The invention relates to an image processing method by which image data representing a 2-dimensional object are input and subjected to specified processing, and the processed image data are output. The invention also relates to an image input device, a control device, an image output device and an image processing system in which this method is employed.
In recent years, copy machines have been developed which can read a document, such as a color photograph, and generate a high-quality copy in which the colors are accurately reproduced. Such copy machines are now used for a wide variety of applications.
However, the resolution of these copy machines is high enough that someone might think it worthwhile to try to run off multiple copies of bank notes, stock certificates, or other documents which may not be legally reproduced. To prevent such one-touch counterfeiting, it has been suggested (Patent Publication 2-210481) that copy machines should be given the capability of recognizing a characteristic pattern on non-reproducible documents so that copies of such documents will not be output.
FIG. 28 shows the general configuration of a device to provide the capability to prevent copying described above. It consists primarily of image generation unit 50, control unit 51, image formation unit 52 and pattern detection unit 53.
The aforesaid image generation unit 50 consists of an image scanner which reads the document and generates red (R), blue (B) and green (G) image data. Control unit 51 inputs these image data and converts them to yellow (Y), magenta (M), cyan (C) and black (K) image data which can be used in image formation unit 52. Image formation unit 52 accepts the converted image data and transcribes them.
Pattern detection unit 53 determines whether the image data generated by image generation unit 50 contain the characteristic pattern which identifies a non-reproducible document. The result of this determination is output to control unit 51. When control unit 51 receives from unit 53 the result that the characteristic pattern has been found, it outputs a control signal (shown in the drawing by dotted lines) to image formation unit 52 or image generation unit 50 to cease operating. With this method, the generation or output of image data identified by the characteristic pattern will be interrupted, and the copying operation will be halted or the entire surface of the copy which is output will be covered with a particular color.
Recently, printers have been developed which are capable of outputting highly accurate color images. Now anyone with an image scanner, a personal computer and a printer can easily make reproductions of color documents which are as accurate as those of high-resolution copy machines. For this reason a demand has sprung up for a device which could be installed in such a system to prevent the reproduction of specified image data and thereby prevent the system from being used for unlawful copying.
The present invention addresses the problems discussed above. One objective is to provide a device which would be able to recognize a characteristic pattern in a document""s image data and control the output of image data based on the result of this recognition. This would be a simple and reliable way to prevent the output of specified image data.
Another objective of this invention is to provide a device able to determine whether there is a means either in the system or connected to it which could detect specific image data as described above and control the output of image data. If it is determined that there is no such device, it would partially or completely halt the function of the system so that output of the specific image data would be completely arrested.
In one embodiment of the present invention, the image data to be processed are color image data consisting of the combination of image data associated with a number of color signals which are input successively.
In another embodiment of the present invention, the specified pattern is detected as follows. For each color signal, all image data except those which will be input last are stored separately. When the final data are input, an image created by combining these data with all the aforesaid image data which have been stored is compared with a reference pattern.
In still another embodiment of the present invention, the method is implemented by a device which detects a specified pattern. This device consists of: a device to store separately all image data for each color signal except those data which are to be input last; a device to compare with a reference pattern an image created by combining, when the last image data have been input, the final input data with all the image data stored in the aforesaid storage device; and a device to determine, based on the result of the comparison performed by the aforesaid comparison device, whether the aforesaid specified pattern can be found in the image data being processed.
In another embodiment of the present invention, the image data for the different color signals are successively compared with a reference image. The result of the comparison for each color signal is stored, and the results of all the comparisons are cumulated to detect the specified pattern.
In another embodiment, the aforesaid means of detecting a specified pattern consists of: a device to compare the image data for each color signal to a specified reference pattern; a device to store for each color signal the result of the comparison performed by the aforesaid comparison device; and a device to cumulate the results of the comparisons for the different color signals which are stored in the aforesaid storage device and determine whether the aforesaid specified pattern can be found in the image data being processed.
In one embodiment of the present invention, an image processing method is employed by which image data representing a 2-dimensional object are input and subjected to specified processing, and the processed image data are output. When it becomes clear at some point during the aforesaid processing that either the processing to determine whether a specified pattern can be found in the image data or the processing to control the output of image data according to the result of the determination will not be executed, the image processing function is partially or completely halted.
Another embodiment of the present invention is a system to implement the processing method described above, consisting of: a device which detects whether the system has a means to determine whether a specified pattern can be found in the image data being processed; a device which detects whether the system has a means to control the output of image data based on the result of the determination made by the aforesaid means of detecting a specified pattern; and a device which halts the function of the system either partially or completely when the first of the aforesaid detection devices detects that the system has no means to determine whether a specified pattern can be found in the image data being processed, or when the second of the aforesaid detection devices detects that the system has no means to control its output.
Other embodiments concern devices used to input image data representing a 2-dimensional object. These input devices have a means to determine whether a specified pattern can be found in the image data being processed and a means to control the output of image data based on the result of the determination made by the means of detecting a specified pattern. The image data which are to be processed are color image data consisting of the combination of image data associated with a number of color signals which are input successively.
In one embodiment, the aforesaid means of detecting a specified pattern consists of: a device to store separately all image data for each color signal except those data which are to be input last; a device to compare with a reference pattern an image created by combining, when the last image data have been input, the final input data with all the image data stored in the aforesaid storage device; and a device to determine, based on the result of the comparison performed by the aforesaid comparison device, whether the aforesaid specified pattern can be found in the image data being processed.
In another embodiment, the aforesaid means of detecting a specified pattern consists of: a device to compare the image data for each color signal to a specified reference pattern; a device to store for each color signal the result of the comparison performed by the aforesaid comparison device; and a device to cumulate the results of the comparisons for the different color signals which are stored in the aforesaid storage device and determine whether the aforesaid specified pattern can be found in the image data being processed.
In still another embodiment, an image input device identical to that described above has, either integral to itself or in a device connected to it, a means to determine whether the system has a device which detects a specified pattern in the image data being processed and a device which controls data output based on the result of the detection made by the device to detect a specified pattern; and a means to halt the function of the device either partially or completely when the aforesaid determination device has determined that the system lacks either the aforesaid device to detect a pattern or the device to control the output.
Other embodiments concern a control device which executes specified processing on image data representing a 2-dimensional object or a device to output image data representing a 2-dimensional object.
In other embodiments of the present invention, an image created by combining the input data with image data entered previously and stored is compared with a reference pattern when the final image data are input. In this way it can be determined whether the image contains the specified pattern. This method makes it possible to execute pattern detection processing on an image created by successively combining image data for multiple color signals.
In some embodiments, the image data for the each color signal are compared with a reference image at the time they are generated. The result of the comparison for each color signal is stored, and the results of all the comparisons are cumulated to determine whether the data contain the specified pattern. This method makes it possible to execute pattern detection processing on a color image created by successively combining image data for multiple color signals.
Finally, in some embodiments of the present invention, when the function of detecting the pattern or the function of controlling the output of image data are not present, the function of the system is partially or completely halted. Thus, if someone should substitute some other device for the device which detects a pattern or controls the output, the function of that other device will be halted and it will become impossible to output image data for the document.